All runners have also been given a black ribbon to wear on their running vest, while many have pledged to cross the finish line with their hand over their hearts.

Runners have been given a black ribbon to wear to honour victims of the Boston bombings (Picture: AFP/Getty)

Today Virgin London Marathon announced that it will also be making a financial donation to The One Fund Boston, which was set up to raise money for victims of the explosions, pledging £2 for every finisher.

With 35,000 people estimated to complete the race it is likely that £70,000 – over $100,000 – will be raised.

Race director Hugh Brasher said: ‘Everyone connected with the London Marathon was shocked by the terrible events in Boston, and we are keen to show our support to the victims’ families and our friends in the running community there.

‘As soon as we heard about The One Fund Boston we decided to make a donation. Our pledge to give £2 for every finisher at the 2013 Virgin London Marathon seemed an appropriate and fitting way to make our contribution.’

Tom Grilk, the race director of the Boston marathon, said the city was ‘deeply gratified’ that citizens were receiving so much support.

He added: ‘We will remember what the runners in London and the organisers of the Virgin London Marathon are doing on Sunday. On behalf of everyone, thank you.’